Automatic reclosing circuit-breaker system



Dec. .22 1925- O. C. TRAVERY AUTOMATIC RECLOSING CIRCUIT BREAKER SYSTEM Filed Dec. 20, I921 Oliver" C-TTQA/GTI? His mtovhfey Patented Dec. 22, 1925 umrsn STATES;

PATENT or icE.

GLIVER C. TRAVER, OF SCHENECTADY, NEW YORK, ASSIGNOB, TO GENERAL ELEC- TRIG COMPANY, A CORPORATION OF NEW YORK.

AUTOMATIC RECIOSING CIRCUIT-BREAKER SY STEM.

Application filed December 20, 1921. Serial 1W0. 523,754.

T 0 all 1.0710112) it may concern."

Be it known that I, OLIVER C. TRAVER, a citizen of the United States, residing at Schenectady, in the county of Schenectady,

State of New York, have invented certain new and useful Improvements in Automatic Reclosing Circuit-l3reaker Systems, of which the following is a specification.

My invention relates to automatic reelosing circuit breaker systems, and particularly to such systems in which a circuit breaker is arranged to connect automatically a source of current to a load circuit as soon as the conditions on the load circuit are such that the circuit breaker can be closed without overloading the source to be connected and in which the load circuit is arranged to be supplied at more than one point.

One object ofmy invention is to provide an automatic reclosing circuit breaker system in whichthe circuit breaker can be closed only when the relative polaritls" of the load circuit and the source" to be connected thereto are'the same and the conditions on the load circuit are such that the circuit breaker can be closed without overloading the source when it is connected thereto by the closing of the circuit breaker.

lily invention will be better understood from the following description taken in connection with the accompanying drawing, and its scope'will be pointed out in the appended claims.

Referring to the drawing which shows one embodiment of my invention, a load circuit 1, 2 is arranged to be supplied from two feeder circuits 3, 4 and 5, 6 which are connected'to the sources of current 7 andS, respectively. It is obvious, however, that both feeder circuits could be connected to the same source if it were so desired. The feeder conductor 5 is arranged to be connected to the load conductor 1 byany suitable switching means such as a circuit breaker 9 which may be closed either automatically or manually, whereas the feeder conductor 4 is arranged to be connected to the load conductor 1 by means of the automatic reclosing circuit breaker ,10. The feeder conductors 3 and 6 may be perma- .nently connected to the load conductor 2.

The circuit breaker 10 shown in the drawing comprises a closing coil 11 which, when energized, maintains the circuit breaker in its closed position. The circuit of the closing coil 11 is connected to the feeder circuit 8, 4 through the contacts 12 of the overload relay 13, the contacts 14 and 15 of the reclosing relay 16, contacts 17 of the relay 18 and contacts 19 of the contactor 20.

The overload relay 13 is provided with a winding 21 which is connected in series either instantly or after a predetermined interval, when the winding 21 is sufficiently energized to operate the relay, but are-not closed until a predetermined interval after the winding 21 1s deenergized.

The reclosing relay 16 is a polarized relay of any suit-able construction and as shown in the drawing it comprisesa mag netic structure having three polar projections 25, 26 and 27, a common'yoke 28 and an armature 29 pivotally mounted in front of the three polar projections. A spring 30 tends to maintain the armature in the position in which the contact 14 which is carried by the armature 29 engagesv the sta tionary contact 31. For the purpose of this specification, this position of the armature will be called the open position and the other position in which the contacts 14 and 15 are in engagement, the reclosing position.

The magnetic structure may be either permanently magnetized or magnetized by a winding 32 equally distributedon the polar projections 25 and 27. This polarizing winding is energized from any suitable source, such as the feeder circuit 3, 4- and is so wound that the polar projections 25 andv 27 are of opposite polarity. The reclosing relay 16 is also provided with an operating winding 34 which is connected across the load circuit 1, 2. This winding is wound on the polar projection 26 so that it is of the same polarity as the polar projection 25, when the polarities of the source? and the load circuit 1, 2 are the same. the magneto-motive force produced by the current in the-operating winding 34 opposes the magneto-motive force produced by current through the portion of the po-' Therefore,

. larizin winding 32 on the polar rojection the action of the spring 30 thereby closing the contacts 14 and 15.

, The contactor is arranged to connect the current limiting resistor 36 in arallel with the terminals of the circuit reaker 10 so thatwhen the circuit breaker is open the resistor 36 is connected in series with the conductors 1 and 4. The contactor is provided with an operating coil 37 which is arranged to be connected across the feeder circuit 3, 4 when the overload relay contacts 12 and the reclosing relay contacts 14 and 31 are closed.

The operating winding 37 is also arranged to be connected across the load circuit 1, 2 in series with the load resistor 36 by means ofthe relay 18, the operating winding 38 of which is also connected across the load circuit in series with the load resistor 36. When the contactor 20 is closed the operatin windings 37 and 38 are both connected acrossthe feeder circuit 3, 4 through the overload relay contacts 12.

It will be noted that the operating winding' 34 of the reclosing relay 16 may be connected to a tap on the current limiting resistor 36. By connecting the operating coil in this manner, a higher voltage is impressed u on the terminals of the operating winding t an would be the case if the winding. were connected. directly across the load circuit.- Consequently, 'a winding having a 1 higher resistance may be used.

he operation of the embodiment ,shown in the draw n is as follows: Under normal operating con -itions the overload relay con tacts 12 are closed and the contactor operating winding 37 and'the relay operating winding 38' are energized. The circuit of the, operating coil 38 extends from the supply conductor 4 through contacts .19 ofthe contactor- 20, operating winding 38 of the relay 18, overload relay contacts 12 to the feeder conductor 3. The energizing circuit.

of the operating windin 37 of the contactor '20'extends from the fee er conductor 4, contactor contacts 19, relay contacts 17, 0 erating winding 37 of contactor 20, over oad relay contacts 12 to the feeder conductor 3.' The circuit breaker 10 is held .in its closed position by the 'energization of the closing coil 11, the circuit of which extends from the feeder conductor 4 through the contacts 19 of the contactor 20, relay contacts 3?, reclosing relay contacts 14 and 15, closreclosingl across t ing coil 11, overload relay contacts-12 to the feeder conductor 3. The windings 32 and 34 of the reclosing relay 16 have full potential impressed thereon so that the relay is held in its reclosing'position, in which position the contacts 14 and 15 are closed.

In case of an overload ora short circuit on the load circuit, 1, 2, the overload relay 13 operates and opens its contacts 12. The

across the load circuit-1, 2. so that if the voltage across the load circuit is above a 'predetermined value and is in the proper direction theireclosing relay'remains in its position. I however, the voltage e load circuit falls to a very low value indicating that the circuit breaker 9 is open the operating winding 34 of the re closing relay is not sufliciently energized to maintain the relay in its reclosing position and the spring 30 moves the armature 29 to its open position in which position the contacts 14 and- 31 are closed thereby completing a circuit for the operating coil 37 of the contactor 20, as soon as the overload relay closes its contacts 12 which does not occur until a predetermined interval after the circuit breaker 10 opens. This circuit extends from the feeder conductor 4 through the reclosing relay contacts 31 and 14, operating winding 37, overload relay contacts 12 to the feeder conductor 3. Contactor 20 then closes and connects the current-limiting resistor 36 in series with the -A small current is now furnished load circuit through the current limiting resistor 36. and this current produces a otential drop across the load resistance. T is drop plus the drop across the right hand section of the'current-limiting resistor 36 beyond the point where the operating coil 34 is connected is available to operate the reclosing relay. As the load resistance increases the voltage impressed upon the opermergers ating winding 34 increases and the reclosing relay 16 closes its contacts 14 and 15 when the resistance increases to a predetermined value. The closing of the contacts 14 and 15 completes the above traced circuit of the closing coil 11 through the contacts 17 and 19 thereby closing the circuit breaker 10.

If, however, the circuit breaker 9 remains closed when the overload or short-circuit occurs on the load circuit, the potential across the load circuit 1, 2, may be suiiicient to maintain the reclosing relay 16 in its reclosing position. The circuit of the closing coil 11 of the circuit breaker 10 is, however, open' at the contacts 17 and 19 of the relay 18 and the contactor 20, respectively, so that the cir-' cuit breaker 10 remains open. The relay 18- remains deenergizcd until the potential across the load circuit increases above a predetermined value. When the load resistance has increased so that the potential across the load circuit is above this predetermined ,value the relay 18 operates and closes its conthen closes and connects the conductors 1 and 4 together.

If the polarities of the load circuit and I I 27 of the reclosing relay 16 would also be reversed so that an increase in the voltage across the load circuit would tend to hold the relay in its open position. Therefore, since the circuit of the closing coil 11 can only be completed through the contacts '14: and 15 of the reclosing relay 16, this coil cannot be energized and therefore the circuit breaker will remain open as long as the potcntials of the load circuit and the source 7 are reversed relative to one another. a

It will be noted that the'subject matter illustrated, described and claimed in this application is disclosed in my copending appli' cation Serial No. 523,7 56 filed DecemberQO, 1921. i i

-While I'have shown and described one embodiment of my invention I do not desire to be limited to the specific arrangement shown, but seek to cover 'in the appended claimsall those modifications falling fairly within the true spirit and scope of my invention. v

lVhat. I claim as new and desire to' secure by Letters Patent of the United States, is: 1. In an automatic reclosing circuit breaker systennthe combination with a direct current load circuit supplied with current at a plurality of points, a direct current supply connection between said load circuit and said supply circuit, and closing means for said:-

circuit breaker, of means responsive-to the relative polarities of the voltages across said supply circuit and said load circuit and the magnitude of the voltage across said load circuit for controlling the operation of said closing means.

2. In an automatic reclosingcircuit breaker system, the combinationuith a load circuit supplied with current at a plurality of points, a supply circuit adapted to be connected to said load circuit, a circuit breaker for controlling the connection between said load circuit and said supply circuit, and closing means for said circuit breaker, of an impedance, switching means adapted to connect said impedance in series with said supply circuit and said load "circuitwhen said circuit breaker is open and the voltage across said load circuit exceeds a predeterminedvalue and means responsive to the voltage across said load circuit adapted to eiiect the operation of said switching means when the voltage across the load circuit drops below a predetermined value and subsequently to effect the operation of said closing means when the voltage across said load circuit exceeds a predetermined value.

3. In an automatic reclosing circuit breaker system, the combination with a load circuit supplied with current at a plurality of points, a supply circuit adapted to be connected to said load circuit, a circuit breaker for. controlling the connection be tween said load circuit and said supply circuit, and closing means for said circuitbreaker, of an impedance, switching means adapted to connect said impedance in series with said supply circuit and said load circuit and a relay responsive to the voltage across said load circuit for effecting the operation of said switching means when the voltage across said load circuit drops below a predetermined minimum value in a predetermined direction relative to the voltage across the supply circuit, and for effecting the operating of said closing means after said switching means has operated in response to the operation of said relay and the voltage across said load. circuit exceeds a predetermined value in a predetermined direction relative to the voltage across said supply circuit.

4. In an automatic reclosing circuit breaker system, the combination with a load circuit supplied with current at a plurality of points, a supply circuit adapted to be connected to said load circuit, a circuit breaker for controlling the connection between said load circuit and said supply circuit,, and closing means for said, circuit breaker, of an impedance, electromagnetic j v of points, a supply circuit adapted to be connected to said 'load circuit, a circuit switching means adapted to connect said impedance in series with said supply circuit and said load circuit,'-a relay connected. to

be responsive to the voltage across said load circuit and arranged to effect the operation of said electromagnetic switching'means ing means after said electromagnetic switch- ;-.1n'g means. has operated in .response to the operationjof said relay 'andtthe voltage across said load circuit exceeds a predetermined.valueina predetermined direction relative to-the voltage across said supply circuit, c. and [an overload relay arranged todecnergize said vvelectromagnetic switching means when thecurrent supplied to said load circuit from-said supply circuit exceeds a predetermined amount.

5. In an" automatic reclosing circuit i breaker system, thecombin'ation with a load circuit supplied withcurrent at a plurality breaker for controlling the connection between said'loadcircult and said supply circuit, and closing means for said circuit breaker, of an'impedanc'e, switching-means adapted to connect said impedance in series with said supply circuit and said load Gib cuit, an auxiliary relay connected to here :sponsive to the voltage across said'l'oad. cir-j cuit when said-switching meanslis' deenergized and-arranged to effect the operation of said switching-means when the voltage;

across said load circuit exceeds a predetermined value, and a control relay connected to be responsive to-the voltage across said load circuit and arranged to effect the operat-ion of said switching means when the voltage across said load circuit drops below a predetermined minimum value in a predetermined direction relative to the direction of-the voltage across the supply circuit and to elfect the operation of said closing means after said switching means has operated-and the voltage across said load circuit exceeds a predetermined value in a predetermined direction relative ,to the direction of the voltage across said supply clrcult.

I 6. In an automatic reclosing circuitbreaker system, the combination with a. load circuit supplied with current at a plurality of points, a supply circuit adapted to, be connected to said load circuit, a circuit breaker for controllingthe connection between said load circuit and said supply circuit, and closing meansfor said circuit breaker, of an im-- pedance, electromagnetic switching means adapted to connect sald'impedance in series with said supply circuit and said load ciramount.

ing meansfi-wheu-vthe voltage across said load circuit exceeds a predetermined value, a control relay connected to .be responsive to the voltage across said load circuit and arranged to effect the operation of said electromagnetic switching means when the voltage across said load circuit drops below a predetermined minimum value in a predetermined direction relative to the direction of the voltage across the supply circuit and to effect the operation of said closing means after said electromagnetic switchingmeans hasoperated and the voltage across said load circuit exceeds apredetermined value in a predetermined direction relative to the di rection of the voltage across said supply circuit, and an overload relay arranged to deenergize said electromagnetic means andjsaid .auxiliary relay when the current supplied to said ,load circuit from said supply circuit exceeds a predetermined 7. ;In an automatic reclosing circuit breaker system, the combination with a load circuit supplied with-current at a plurality of.'points,a supply circuit adapted 'to be con nected to said load circuit, a circuit breaker for controlling the connection between said load circuit and said supply circuit, and closing means for said circuit breaker, of an impedance, switching means adapted to con nect said impedance in series with said supply-circuit and said load circuit when said circuit breaker is open, and a polarized relay controlling the operation of said switching means and the operation of said closing means comprising an operating winding connected in shunt to the load on said load circuit and a polarizing winding connected in shunt to the supply circuit.

switching 8. In an automatic reclosing circuit breaker system, the combination with a load circuit supplied with current at a plurality of points, a. supply circuit adapted to be connected to said load circuit, a circuit breaker for controlling the connection between said load circuit and said supply circuit, and closing means for said circuit breaker, of an impedance, switching means adapted to con? nect said impedance in series with said supply circuit and said load circuit when said circuit breaker is open, and a polarized relay controlling the operation of said switching means and the operation of said closing means comprising a polarizing winding connected in shuntto the supply circuit and an operating winding having one terminal con nected to said impedance and having its other terminal connected to the load circuit so that said control winding isin shunt with the load on said load circuit and aportion of said impedance.

9. In an automatic reclosing circuit breaker system, the combination with a load circuit supplied with current at aplurality of points, a supply circuit adapted to be connected to said load circuit, a circuit breaker for controlling the connection between said load circuit and said supply circuit, and a- ,closing coil for said circuit breaker adapted to close said breaker upon the energizatipn thereof, of means responsive to the potential across said load circuit for controlling the circuit of said closing coil, and means reing means for'said circuit breaker, of an impedance, switching means adapted to connectsaid impedance in series with said supply circuit and said load circuit, a relay connected to be responsive to the voltage across said load circuitior' efiecting the operation of said electromagnetic switching means to connect with said impedance in circuit when the voltage across said load circuit drops below a predetermined minimum value and arranged to elfect the operation of said closing means when said impedance'is connected in circuit and the voltage across saidload circuit exceeds a predetermined value, and-an overload relay arranged to deenergize said electromagnetic switching means when the current supplied to said lead circuitfrom said supply circuit exceeds a predetermined amount.

11. In. an automatic reclosing circuit breaker system, the combination of a load circuit suppl-ied'with current at a' plurality of points, a supply circuit adapted to be connected to said circuit, a circuit breaker for controlling the connection between said load circuit and. said supply circuit and closing means for's'aid circuit breaker, .of

-' an-impedance, switching means adapted to connectsaid impedance in series with said supply circuit and said load circuit, a con- ,trol relay connected to be responsive to the voltage across said load circuit 'for effecting the operation of said switching means to connect saidimpedance in circuit when the voltage across said load circuit drops below a predetermined minimum value and arranged to effect the operation of said across said load circuit remains above said predetermined minimum value arranged to effect the operation of said switching means whenthe voltage across said load circuit exceeds a predetermined value, and contact. means on said switching means and said control relay arranged to control a circuit to effect the operation of said closing means when the operation of said switching means is effected by said auxiliary relay.

12. In an automatic reclosing circuit 80. breaker system, the combination of a load circuit supplied with current at a .pluralityof points, a supply circuit adapted to be connected 'to said circuit, a circuit'bre'aker for controlling the connection between said load circuit and said supply circuit and closingmeans 'for said circuit breaker, of an impedance, electromagnetic switching means adaptedto connect said impedance in series with said supply circuit and said load circuit, a control relay connected to be responsive to the voltage across said load circuit for effecting the operation of said electromagnetic switching means to connect said impedance in circuit when the voltage across saidload circuit drops below a predetermined minimum value and arranged to effect the operation of said closing means when said impedance is connected in circuit and thevoltage across said load circuitexceeds a predetermined value, an auxiliary relay connected to be responsive to the voltage across said load circuit when said circuit breaker opens and the voltage across said load circuit remains above said predetermined minimum value arranged to 'effeet the operation of said electromagnetic switching means when the voltage across said load circuit exceeds a predetermined value, contact means on said electromagnetic 1 switching means and said control relay arranged tocontrol a circuit to effect the operation of said'closing means when the operation of said electromagnetic switchingv means is .efi'ected by said auxiliary relay, 1

andan overload relay arranged to deener-,

gize. said electromagnetic switching means and said auxiliary relay when the current supplied to said load circuit from saidsupply circuit exceeds a predetermined amount.

In witness whereof, I have hereunto set my hand this 19thday of December, 1921.

OLIVER o. TRAVER. 

